The Great Barrier Reef has already been badly damaged by global warming during three extreme heatwaves, in 1998, 2002 and 2016. A new bleaching event is under way now.

As shown in a study published in Nature today, climate change is not some distant future threat. It has already degraded large tracts of the Great Barrier Reef over the past two decades.

The extreme marine heatwave in 2016 killed two-thirds of the corals along a 700km stretch of the northern Great Barrier Reef, from Port Douglas to Papua New Guinea. It was a game-changer for the reef and for how we manage it.

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